/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.feilong.lib.beanutils;

import java.io.Serializable;
import java.lang.reflect.Array;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.beanutils.DynaBean;

/**
 * <p>
 * Minimal implementation of the <code>DynaBean</code> interface. Can be
 * used as a convenience base class for more sophisticated implementations.
 * </p>
 *
 * <p>
 * <strong>IMPLEMENTATION NOTE</strong> - Instances of this class that are
 * accessed from multiple threads simultaneously need to be synchronized.
 * </p>
 *
 * <p>
 * <strong>IMPLEMENTATION NOTE</strong> - Instances of this class can be
 * successfully serialized and deserialized <strong>ONLY</strong> if all
 * property values are <code>Serializable</code>.
 * </p>
 *
 * @version $Id$
 */

public class BasicDynaBean implements DynaBean,Serializable{

    // ---------------------------------------------------------- Constructors

    /**
     * 
     */
    private static final long serialVersionUID = -345115896914191203L;

    /**
     * Construct a new <code>DynaBean</code> associated with the specified
     * <code>DynaClass</code> instance.
     *
     * @param dynaClass
     *            The DynaClass we are associated with
     */
    public BasicDynaBean(final DynaClass dynaClass){

        super();
        this.dynaClass = dynaClass;

    }

    // ---------------------------------------------------- Instance Variables

    /**
     * The <code>DynaClass</code> "base class" that this DynaBean
     * is associated with.
     */
    protected DynaClass                   dynaClass = null;

    /**
     * The set of property values for this DynaBean, keyed by property name.
     */
    protected HashMap<String, Object>     values    = new HashMap<>();

    /** Map decorator for this DynaBean */
    private transient Map<String, Object> mapDecorator;

    /**
     * Return a Map representation of this DynaBean.
     * </p>
     * This, for example, could be used in JSTL in the following way to access
     * a DynaBean's <code>fooProperty</code>:
     * <ul>
     * <li><code>${myDynaBean.<b>map</b>.fooProperty}</code></li>
     * </ul>
     *
     * @return a Map representation of this DynaBean
     * @since 1.8.0
     */
    public Map<String, Object> getMap(){

        // cache the Map
        if (mapDecorator == null){
            mapDecorator = new DynaBeanPropertyMapDecorator(this);
        }
        return mapDecorator;

    }

    // ------------------------------------------------------ DynaBean Methods

    /**
     * Does the specified mapped property contain a value for the specified
     * key value?
     *
     * @param name
     *            Name of the property to check
     * @param key
     *            Name of the key to check
     * @return <code>true</code> if the mapped property contains a value for
     *         the specified key, otherwise <code>false</code>
     *
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     */
    @Override
    public boolean contains(final String name,final String key){

        final Object value = values.get(name);
        if (value == null){
            throw new NullPointerException("No mapped value for '" + name + "(" + key + ")'");
        }else if (value instanceof Map){
            return (((Map<?, ?>) value).containsKey(key));
        }else{
            throw new IllegalArgumentException("Non-mapped property for '" + name + "(" + key + ")'");
        }

    }

    /**
     * Return the value of a simple property with the specified name.
     *
     * @param name
     *            Name of the property whose value is to be retrieved
     * @return The property's value
     *
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     */
    @Override
    public Object get(final String name){

        // Return any non-null value for the specified property
        final Object value = values.get(name);
        if (value != null){
            return (value);
        }

        // Return a null value for a non-primitive property
        final Class<?> type = getDynaProperty(name).getType();
        if (!type.isPrimitive()){
            return (value);
        }

        // Manufacture default values for primitive properties
        if (type == Boolean.TYPE){
            return (Boolean.FALSE);
        }else if (type == Byte.TYPE){
            return (new Byte((byte) 0));
        }else if (type == Character.TYPE){
            return (new Character((char) 0));
        }else if (type == Double.TYPE){
            return (new Double(0.0));
        }else if (type == Float.TYPE){
            return (new Float((float) 0.0));
        }else if (type == Integer.TYPE){
            return (new Integer(0));
        }else if (type == Long.TYPE){
            return (new Long(0));
        }else if (type == Short.TYPE){
            return (new Short((short) 0));
        }else{
            return (null);
        }

    }

    /**
     * Return the value of an indexed property with the specified name.
     *
     * @param name
     *            Name of the property whose value is to be retrieved
     * @param index
     *            Index of the value to be retrieved
     * @return The indexed property's value
     *
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     * @throws IllegalArgumentException
     *             if the specified property
     *             exists, but is not indexed
     * @throws IndexOutOfBoundsException
     *             if the specified index
     *             is outside the range of the underlying property
     * @throws NullPointerException
     *             if no array or List has been
     *             initialized for this property
     */
    @Override
    public Object get(final String name,final int index){

        final Object value = values.get(name);
        if (value == null){
            throw new NullPointerException("No indexed value for '" + name + "[" + index + "]'");
        }else if (value.getClass().isArray()){
            return (Array.get(value, index));
        }else if (value instanceof List){
            return ((List<?>) value).get(index);
        }else{
            throw new IllegalArgumentException("Non-indexed property for '" + name + "[" + index + "]'");
        }

    }

    /**
     * Return the value of a mapped property with the specified name,
     * or <code>null</code> if there is no value for the specified key.
     *
     * @param name
     *            Name of the property whose value is to be retrieved
     * @param key
     *            Key of the value to be retrieved
     * @return The mapped property's value
     *
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     * @throws IllegalArgumentException
     *             if the specified property
     *             exists, but is not mapped
     */
    @Override
    public Object get(final String name,final String key){

        final Object value = values.get(name);
        if (value == null){
            throw new NullPointerException("No mapped value for '" + name + "(" + key + ")'");
        }else if (value instanceof Map){
            return (((Map<?, ?>) value).get(key));
        }else{
            throw new IllegalArgumentException("Non-mapped property for '" + name + "(" + key + ")'");
        }

    }

    /**
     * Return the <code>DynaClass</code> instance that describes the set of
     * properties available for this DynaBean.
     *
     * @return The associated DynaClass
     */
    @Override
    public DynaClass getDynaClass(){

        return (this.dynaClass);

    }

    /**
     * Remove any existing value for the specified key on the
     * specified mapped property.
     *
     * @param name
     *            Name of the property for which a value is to
     *            be removed
     * @param key
     *            Key of the value to be removed
     *
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     */
    @Override
    public void remove(final String name,final String key){

        final Object value = values.get(name);
        if (value == null){
            throw new NullPointerException("No mapped value for '" + name + "(" + key + ")'");
        }else if (value instanceof Map){
            ((Map<?, ?>) value).remove(key);
        }else{
            throw new IllegalArgumentException("Non-mapped property for '" + name + "(" + key + ")'");
        }

    }

    /**
     * Set the value of a simple property with the specified name.
     *
     * @param name
     *            Name of the property whose value is to be set
     * @param value
     *            Value to which this property is to be set
     *
     * @throws ConversionException
     *             if the specified value cannot be
     *             converted to the type required for this property
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     * @throws NullPointerException
     *             if an attempt is made to set a
     *             primitive property to null
     */
    @Override
    public void set(final String name,final Object value){

        final DynaProperty descriptor = getDynaProperty(name);
        if (value == null){
            if (descriptor.getType().isPrimitive()){
                throw new NullPointerException("Primitive value for '" + name + "'");
            }
        }else if (!isAssignable(descriptor.getType(), value.getClass())){
            throw new ConversionException(
                            "Cannot assign value of type '" + value.getClass().getName() + "' to property '" + name + "' of type '"
                                            + descriptor.getType().getName() + "'");
        }
        values.put(name, value);

    }

    /**
     * Set the value of an indexed property with the specified name.
     *
     * @param name
     *            Name of the property whose value is to be set
     * @param index
     *            Index of the property to be set
     * @param value
     *            Value to which this property is to be set
     *
     * @throws ConversionException
     *             if the specified value cannot be
     *             converted to the type required for this property
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     * @throws IllegalArgumentException
     *             if the specified property
     *             exists, but is not indexed
     * @throws IndexOutOfBoundsException
     *             if the specified index
     *             is outside the range of the underlying property
     */
    @Override
    public void set(final String name,final int index,final Object value){

        final Object prop = values.get(name);
        if (prop == null){
            throw new NullPointerException("No indexed value for '" + name + "[" + index + "]'");
        }else if (prop.getClass().isArray()){
            Array.set(prop, index, value);
        }else if (prop instanceof List){
            try{
                @SuppressWarnings("unchecked")
                final
                // This is safe to cast because list properties are always
                // of type Object
                List<Object> list = (List<Object>) prop;
                list.set(index, value);
            }catch (final ClassCastException e){
                throw new ConversionException(e.getMessage());
            }
        }else{
            throw new IllegalArgumentException("Non-indexed property for '" + name + "[" + index + "]'");
        }

    }

    /**
     * Set the value of a mapped property with the specified name.
     *
     * @param name
     *            Name of the property whose value is to be set
     * @param key
     *            Key of the property to be set
     * @param value
     *            Value to which this property is to be set
     *
     * @throws ConversionException
     *             if the specified value cannot be
     *             converted to the type required for this property
     * @throws IllegalArgumentException
     *             if there is no property
     *             of the specified name
     * @throws IllegalArgumentException
     *             if the specified property
     *             exists, but is not mapped
     */
    @Override
    public void set(final String name,final String key,final Object value){

        final Object prop = values.get(name);
        if (prop == null){
            throw new NullPointerException("No mapped value for '" + name + "(" + key + ")'");
        }else if (prop instanceof Map){
            @SuppressWarnings("unchecked")
            final
            // This is safe to cast because mapped properties are always
            // maps of types String -> Object
            Map<String, Object> map = (Map<String, Object>) prop;
            map.put(key, value);
        }else{
            throw new IllegalArgumentException("Non-mapped property for '" + name + "(" + key + ")'");
        }

    }

    // ------------------------------------------------------ Protected Methods

    /**
     * Return the property descriptor for the specified property name.
     *
     * @param name
     *            Name of the property for which to retrieve the descriptor
     * @return The property descriptor
     *
     * @throws IllegalArgumentException
     *             if this is not a valid property
     *             name for our DynaClass
     */
    protected DynaProperty getDynaProperty(final String name){

        final DynaProperty descriptor = getDynaClass().getDynaProperty(name);
        if (descriptor == null){
            throw new IllegalArgumentException("Invalid property name '" + name + "'");
        }
        return (descriptor);

    }

    /**
     * Is an object of the source class assignable to the destination class?
     *
     * @param dest
     *            Destination class
     * @param source
     *            Source class
     * @return <code>true</code> if the source class is assignable to the
     *         destination class, otherwise <code>false</code>
     */
    protected boolean isAssignable(final Class<?> dest,final Class<?> source){

        if (dest.isAssignableFrom(source) || ((dest == Boolean.TYPE) && (source == Boolean.class))
                        || ((dest == Byte.TYPE) && (source == Byte.class)) || ((dest == Character.TYPE) && (source == Character.class))
                        || ((dest == Double.TYPE) && (source == Double.class)) || ((dest == Float.TYPE) && (source == Float.class))
                        || ((dest == Integer.TYPE) && (source == Integer.class)) || ((dest == Long.TYPE) && (source == Long.class))
                        || ((dest == Short.TYPE) && (source == Short.class))){
            return (true);
        }else{
            return (false);
        }

    }

}
